/*
██████╗ █████╗ ███████╗██╗ ██╗██╗██████╗
██╔══██╗██╔══██╗██╔════╝██║ ██║██║██╔══██╗
██████╔╝███████║███████╗███████║██║██║ ██║
██╔══██╗██╔══██║╚════██║██╔══██║██║██║ ██║
██║ ██║██║ ██║███████║██║ ██║██║██████╔╝
╚═╝ ╚═╝╚═╝ ╚═╝╚══════╝╚═╝ ╚═╝╚═╝╚═════╝
*/
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ll long long
#define ull unsigned long long
#define ld long double
#define str string
#define ch char
#define db double
#define pb push_back
#define ff first
#define ss second
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define YES cout<<"YES\n";
#define NO cout<<"NO\n";
#define Bob cout<<"Bob\n";
#define Alice cout<<"Alice\n";
#define ordered_set tree<pair<ll, ll>, null_type,less<pair<ll,ll>>,rb_tree_tag,tree_order_statistics_node_update>
const ll MOD=1e9+7;
const ll INF = 10000000000;
bool duzdu(ll target,vector<ll>v){
vector<bool>dp(target+1,false);
dp[0]=true;
for(ll i = 0;i<v.size();i++){
for(ll j = target;j>=v[i];j--){
if(dp[j-v[i]]){
dp[j]=true;
}
}
}
return dp[target];
}
void solve(){
ll n;
cin>>n;
vector<ll>v(n);
ll sum = 0;
for(int i = 0;i<n;i++){
cin>>v[i];
sum+=v[i];
}
if(sum&1){
cout<<0;
return;
}
vector<ll>ans;
for(ll j = 1;j<=500;j++){
bool ok = true;
for(ll i = 0;i<n;i++){
ll alma = v[i];
vector<ll>a = v;
a.erase(a.begin()+i);
a.pb(j);
ll sum1 = sum-alma+j;
if(sum1&1){
ok = false;
break;
}
ll target = sum1/2;
if(!(duzdu(target,a))){
ok = false;
break;
}
}
if(ok){
ans.pb(j);
}
}
cout<<ans.size()<<"\n";
for(auto p : ans)cout<<p<<" ";
}
signed main(){
ll t=1;
//cin>>t;
while(t--){
solve();
}
return 0;
}
